The Evolution of Genus Homo

Fig. 7-8, p. 165

Homo habilis

“Handy man.” The first fossil members of the genus

Homo appearing 2.5 million years ago, with larger brains and smaller faces than australopithecines.

Lower Paleolithic

The first part of the Old Stone Age. Its beginning is marked by the

appearance 2.6 million years ago of Oldowan tools.

Lower Paleolithic Tools

The earliest stone tools have been found in the vicinity of Lake Turkana in northwestern Kenya, in southern Ethiopia, in Olduvai Gorge in Tanzania, and in Hadar in Ethiopia— often in the same geological strata as Homo habilis fossils.

These tools consist of implements made using a system of manufacture called the percussion method.

Sharp-edged flakes were obtained from a stone either by using another stone as a hammer or by striking the pebble against a large rock to remove the flakes.

Percussion Method

By 2.5 million years ago, early Homo in Africa had invented the percussion method of stone tool manufacture.

This technological breakthrough, which is associated with a significant increase in brain size, made possible the butchering of meat from scavenged carcasses.

Oldowan A toolmaking tradition from Africa associated

with early Homo.

Core Tools Tools made by taking flakes off a stone

nucleus.

Flake Tools Tools made from the flakes removed from a

stone core.

The Evolution of Genus Homo

To New Lands What prompted H. erectus to leave the

savannas to which they were apparently so well adapted?

We can’t know the answer for sure, but a good guess is that the spread of H. erectus was simply the outcome of their reproductive success. Their big brains enabled them to exploit the savannas to a greater extent than had other hominins to date.

Cranial Capacity in Homo erectus

Homo erectus

China 1.8 mya Ethiopia 1 mya Georgia 1.75 mya Italy 800,000 ya Java 1.8 mya Kenya 1.5mya Tanzania 1.4 mya Mean brain size 984 ml

Homo erectus Fossils

These casts of the skull cap and thighbone of Homo erectus were made from the original bones found by Eugene Dubois at Trinil, Java.

Fig. 7-5, p. 162

Alternate Designations For Homo erectus Fossils From Eurasia And AfricaName Explanation

Homo ergaster

Some paleoanthropologists feel the large-brained successors to H. habilis from Africa and Asia are too different to be placed in the same species.They use H. ergaster for the African specimens, saving H. erectus for the Asian fossils. Turkana boyAcheulean hand-axe Brain size 800ml-880ml

Acheulean Hand-axe

To fabricate this Acheulean hand-axe from flint, the toolmaker imposed a standardized arbitrary form on the naturally occurring raw material.

p. 165

p. 158

Alternate Designations For Homo erectus Fossils From Eurasia And Africa

Name Explanation

Homo antecessor This name was coined by splitters for the earliest Homo fossils from western Europe discovered in Spain; antecessor is Latin for “explorer” or “pioneer.” 780.000 yaBrain size 1,000ml

Homo heidelbergensis

Named for the Mauer jaw, this name is now used as a designation for all European fossils from about 500,000 years ago until the appearance of the Neandertals. Brain size mean 1,247 ml

The Evolution of Genus Homo

Big Brains, Archaic Skulls H. neanderthalensis, H.

heidelbergensis, and H. antecessor are marked by brain sizes within the modern human range that, indeed, match or approximate the modern human average; nonetheless, they have other features, especially of the cranium, that retain primitive characteristics.

Levallois Technique A tool technology involving striking uniform flakes form a

prepared core

Levalloisian Technique

Drawing A shows the preparatory flaking of the stone core; B, the same on the top surface; C, the final step of detaching a flake; and D, the final step of detaching a flake of a size and shape predetermined by the preceding steps.

p. 169

Use of Fire

The use of fire is another sign of H. erectus’ developing culture and technology.

The 700,000-year-old Kao Poh Nam rock shelter in Thailand provides compelling evidence for deliberate controlled use of fire.

Homo erectus may have been using fire even earlier, based on evidence from Swartkrans in South Africa. In deposits estimated to date between 1

and1.3 million years ago, bones have been found that had been heated to temperatures far in excess of what one would expect as the result of natural fires.

Kao Poh Nam Rock Shelter

Archaeologists excavate a hearth at a rock shelter in Kao Poh Nam, Thailand.

This hearth testifies to human use of controlled fire 700,000 years ago.